Ghost Wind of the Cosmic Dawn: How Lyman-alpha Destroys Stellar Cradles ✦
A Lyman-alpha photon in dense gas is not just light. Trapped in an atomic maze, it darts about, pushing matter with each bounce. Thousands, millions of times. Thus is born a ghostly wind capable of sweeping away entire stellar nurseries. The first simulations showed: this wind is tens of times stronger than direct light. Perhaps it was this wind that sculpted the first galaxies.
🎯 The Lyman-alpha line is the brightest spectral line of hydrogen. In optically thick clouds, a single photon can scatter millions of times before escaping. With each scattering, it transfers momentum to the gas, and in a dust-poor environment, the total pressure becomes comparable to that of all other stellar photons combined!
🎬 The idea of using light pressure isn't new: in Arthur C. Clarke's novel 'Rendezvous with Rama,' a solar sail catches photons. Lyα feedback is a natural 'supersail,' where multiple scattering amplifies the effect tens of times, but here it can both accelerate and destroy gas clouds around stars.